1
MRF173 MRF173CQMOTOROLA RF DEVICE DATA
The RF MOSFET Line
 
  
N–Channel Enhancement Mode MOSFETs
Designed for broadband commercial and military applications up to 200 MHz
frequency range. The high–power, high–gain and broadband performance of
these devices make possible solid state transmitters for FM broadcast or TV
channel frequency bands.
Guaranteed Performance at 150 MHz, 28 V:
Output Power = 80 W
Gain = 11 dB (13 dB Typ)
Efficiency = 55% Min. (60% Typ)
Low Thermal Resistance
Ruggedness Tested at Rated Output Power
Nitride Passivated Die for Enhanced Reliability
Low Noise Figure — 1.5 dB Typ at 2.0 A, 150 MHz
Excellent Thermal Stability; Suited for Class A Operation
MAXIMUM RATINGS
Rating Symbol Value Unit
Drain–Source Voltage VDSS 65 Vdc
Drain–Gate Voltage VDGO 65 Vdc
Gate–Source Voltage VGS ±40 Vdc
Drain Current — Continuous ID9.0 Adc
Total Device Dissipation @ TC = 25°C
Derate above 25°CPD220
1.26 Watts
W/°C
Storage Temperature Range Tstg –65 to +150 °C
Operating Temperature Range TJ200 °C
THERMAL CHARACTERISTICS
Characteristic Symbol Max Unit
Thermal Resistance, Junction to Case RθJC 0.8 °C/W
ELECTRICAL CHARACTERISTICS (TC = 25°C unless otherwise noted)
Characteristic Symbol Min Typ Max Unit
OFF CHARACTERISTICS
Drain–Source Breakdown Voltage (VDS = 0 V, VGS = 0 V) ID = 50 mA V(BR)DSS 65 V
Zero Gate Voltage Drain Current (VDS = 28 V, VGS = 0 V) IDSS 2.0 mA
Gate–Source Leakage Current (VGS = 40 V, VDS = 0 V) IGSS 1.0 µA
ON CHARACTERISTICS
Gate Threshold Voltage (VDS = 10 V, ID = 50 mA) VGS(th) 1.0 3.0 6.0 V
Drain–Source On–V oltage (VDS(on), VGS = 10 V, ID = 3.0 A) VDS(on) 1.4 V
Forward T ransconductance (VDS = 10 V, ID = 2.0 A) gfs 1.8 2.2 mhos
(continued)
NOTE — CAUTION — MOS devices are susceptible to damage from electrostatic charge. Reasonable precautions in handling and
packaging MOS devices should be observed.
Order this document
by MRF173/D

SEMICONDUCTOR TECHNICAL DATA


80 W, 28 V, 175 MHz
N–CHANNEL
BROADBAND
RF POWER MOSFETs
CASE 211–11, STYLE 2
(MRF173)
CASE 316–01, STYLE 2
(MRF173CQ)
Motorola, Inc. 1997
D
S
G
REV 8
MRF173 MRF173CQ
2MOTOROLA RF DEVICE DATA
ELECTRICAL CHARACTERISTICS — continued (TC = 25°C unless otherwise noted)
Characteristic Symbol Min Typ Max Unit
DYNAMIC CHARACTERISTICS
Input Capacitance (VDS = 28 V, VGS = 0 V, f = 1.0 MHz) Ciss 110 pF
Output Capacitance (VDS = 28 V, VGS = 0 V, f = 1.0 MHz) Coss 105 pF
Reverse Transfer Capacitance (VDS = 28 V, VGS = 0 V, f = 1.0 MHz) Crss 10 pF
FUNCTIONAL CHARACTERISTICS
Noise Figure (VDD = 28 V, f = 150 MHz, IDQ = 50 mA) NF 1.5 dB
Common Source Power Gain
(VDD = 28 V, Pout = 80 W, f = 150 MHz, IDQ = 50 mA) Gps 11 13 dB
Drain Efficiency (VDD = 28 V, Pout = 80 W, f = 150 MHz, IDQ = 50 mA) η55 60 %
Electrical Ruggedness
(VDD = 28 V, Pout = 80 W, f = 150 MHz, IDQ = 50 mA)
Load VSWR 30:1 at all phase angles
ψNo Degradation in Output Power
Series Equivalent Input Impedance MRF173
(VDD = 28 V, Pout = 80 W, f = 150 MHz, IDQ = 50 mA) Zin 2.99j4.5 Ohms
Series Equivalent Output Impedance MRF173
(VDD = 28 V, Pout = 80 W, f = 150 MHz, IDQ = 50 mA) Zout 2.68j1.3 Ohms
Series Equivalent Input Impedance MRF173CQ
(VDD = 28 V, Pout = 80 W, f = 150 MHz, IDQ = 50 mA) Zin 1.35j5.15 Ohms
Series Equivalent Output Impedance MRF173CQ
(VDD = 28 V, Pout = 80 W, f = 150 MHz, IDQ = 50 mA) Zout 2.72j149 Ohms
C1, C15 — 470 pF Unelco
C2, C3, C5 — 9–180 pF, Arco 463
C4, C6 — 15 pF, Unelco
C7 — 5–80 pF, Arco 462
C8, C10, C14, C16 — 0.1 µF
C9, C13 — 50 µF, 50 Vdc
C11, C12 — 680 pF, Feed Through
L1 — #16 A WG, 1–1/4 Turns, 0.3 ID
L2 — #16 A WG Hairpin 1 long
L3 — #14 A WG Hairpin 0.8 long
L4 — #14 A WG Hairpin 1.1 long
RFC1 — Ferroxcube VK200–19/4B
RFC2 — 18 T urns #18 AWG Enameled, 0.3 ID
R1 — 10 k, 10 Turns Bourns
R2 — 1.8 k, 1/4 W
R3 — 10 k, 1/2 W
Z1 — 1N5925A Motorola Zener
R1
C11
R2
C8 C9 Z1 C10 C13 C14
C12
C1
C2 C3
C4 C5 C6 C7
C15
L1 L2
L3 L4
RF
INPUT
RF
OUTPUT
VDD = 28 V +
RFC1
RFC2
R3
C16
++
D.U.T.
Figure 1. 150 MHz Test Circuit
Vdc
3
MRF173 MRF173CQMOTOROLA RF DEVICE DATA
TYPICAL CHARACTERISTICS
8910
0234 7156
120
100
60
40
0
20
80
150 MHz
200 MHz
VDD = 28 V
IDQ = 50 mA
Pin, INPUT POWER (W ATTS)
P , OUTPUT POWER (W ATTS)
out
Figure 2. Output Power versus Input Power
Pin, INPUT POWER (WATTS)
P , OUTPUT POWER (W ATTS)
out
Figure 3. Output Power versus Input Power
14
0 2.0 4.0 6.0 128.0 10
80
70
60
50
40
0
10
30
20
f = 100 MHz
150 MHz
200 MHz
26 28 30
10 14 16 18 2412 20 22
140
120
60
40
0
20
80
VDD, SUPPLY VOLTAGE (VOLTS)
P , OUTPUT POWER (W ATTS)
out
Figure 4. Output Power versus Supply Voltage
100 3.0 W
2.0 W
1.0 W
Pin = 4.0 W
26 28 30
10 14 16 18 2412 20 22
140
120
60
40
0
20
80
VDD, SUPPLY VOLTAGE (VOLTS)
P , OUTPUT POWER (W ATTS)
out
Figure 5. Output Power versus Supply Voltage
100 6.0 W
4.0 W
2.0 W
Pin = 8.0 W
26 28 30
10 14 16 18 2412 20 22
140
120
60
40
0
20
80
VDD, SUPPLY VOLTAGE (VOLTS)
P , OUTPUT POWER (W ATTS)
out
Figure 6. Output Power versus Supply Voltage
100 10 W
6.0 W
4.0 W
Pin = 14 W
22
20
18
16
12
8.0
6.0
4.0
2.020 40 60 80 100 120 140 160 200 220
f, FREQUENCY (MHz) 180
14
10
G , POWER GAIN (dB)
PS
Pout = 80 W
VDD = 28 V
IDQ = 50 mA
Figure 7. Power Gain versus Frequency
VDD = 13.5 V
IDQ = 50 mA
f = 100 MHz
IDQ = 50 mA
f = 100 MHz IDQ = 50 mA
f = 150 MHz
IDQ = 50 mA
f = 200 MHz
MRF173 MRF173CQ
4MOTOROLA RF DEVICE DATA
Figure 8. Output Power versus Gate Voltage Figure 9. Drain Current versus Gate Voltage
Figure 10. Gate–Source Voltage versus
Case Temperature Figure 11. Capacitance versus Drain Voltage
Figure 12. DC Safe Operating Area
80
70
60
50
40
30
20
10
0
–14 –12 –10 –8.0 –6.0 –4.0 –2.0 0 2.0 6.0
VGS, GATE–SOURCE VOLTAGE (VOLTS) 4.0
P , OUTPUT POWER (WATTS)
out
VGS, GATE–SOURCE VOLTAGE (VOLTS)
I , DRAIN CURRENT (AMPS)
D
VDS = 10 V
VGS(th) = 3.0 V
6.0
5.0
4.0
3.0
2.0
1.0
00 1.0 2.0 3.0 4.0 5.0 6.0
175
–25 0 25 75 100 125 15050
1.2
1.1
1.0
0.9
0.7
0.8
TC, CASE TEMPERATURE (C
°
)
V , GATE-SOURCE VOLTAGE (NORMALIZED)
GS
VDS = 28 V
ID = 3.0 A
1.0 A
500 mA
50 mA
28
04812162024
420
360
300
240
180
0
120
60
VDS, DRAIN–SOURCE VOLTAGE (VOL TS)
VGS = 0 V
FREQ = 1 MHz
Coss
Crss
100
1.0 2.0 4.0 6.0 10 20 40 60
10
5.0
2.0
1.0
0.5
0.1
0.2
VDS, DRAIN–SOURCE VOLTAGE (VOL TS)
I , DRAIN CURRENT (AMPS)
D
TC = 25
°
C
f = 150 MHz
Pin = CONSTANT
VDS = 28 V
IDQ = 50 mA
VGS(th) = 3.0 V
Coss, CAP ACITANCE (pF)
Crss, Ciss, CAPACITANCE (pF)
140
120
100
80
60
40
20
0
Ciss
5
MRF173 MRF173CQMOTOROLA RF DEVICE DATA
DESIGN CONSIDERATIONS
The MRF173/CQ is a RF MOSFET power N–channel en-
hancement mode field–effect transistor (FET) designed for
VHF power amplifier applications. Motorola’s RF MOSFETs
feature a vertical structure with a planar design, thus avoid-
ing the processing difficulties associated with V–groove pow-
er FETs.
Motorola Application Note AN211A, FETs in Theory and
Practice, is suggested reading for those not familiar with the
construction and characteristics of FETs.
The major advantages of RF power FETs include high
gain, low noise, simple bias systems, relative immunity from
thermal runaway, and the ability to withstand severely mis-
matched loads without suffering damage. Power output can
be varied over a wide range with a low power dc control sig-
nal, thus facilitating manual gain control, ALC and modula-
tion.
DC BIAS
The MRF173/CQ is an enhancement mode FET and,
therefore, does not conduct when drain voltage is ap-
plied. Drain current flows when a positive voltage is ap-
plied to the gate. See Figure 9 for a typical plot of drain
current versus gate voltage. RF power FETs require for-
ward bias for optimum performance. The value of quies-
cent drain current (IDQ) is not critical for many
applications. The MRF173/CQ was characterized at IDQ =
50 mA, which is the suggested minimum value of IDQ. For
special applications such as linear amplification, IDQ may
have to be selected to optimize the critical parameters.
The gate is a dc open circuit and draws no current. There-
fore, the gate bias circuit may generally be just a simple re-
sistive divider network. Some special applications may
require a more elaborate bias system.
GAIN CONTROL
Power output of the MRF173/CQ may be controlled from its
rated value down to zero (negative gain) by varying the dc
gate voltage. This feature facilitates the design of manual gain
control, AGC/ALC and modulation systems. (see Figure 8.)
AMPLIFIER DESIGN
Impedance matching networks similar to those used with
bipolar VHF transistors are suitable for MRF173/CQ. See
Motorola Application Note AN721, Impedance Matching
Networks Applied to RF Power Transistors. The higher input
impedance of RF MOSFETs helps ease the task of broad-
band network design. Both small–signal scattering parame-
ters and large–signal impedances are provided. While the
s–parameters will not produce an exact design solution for
high power operation, they do yield a good first approxima-
tion. This is an additional advantage of RF MOS power FETs.
MRF173 MRF173CQ
6MOTOROLA RF DEVICE DATA
PACKAGE DIMENSIONS
CASE 211–11
ISSUE N
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
A
UM
M
Q
RB
1
4
32
D
K
E
SEATING
PLANE
C
J
H
DIM MIN MAX MIN MAX
MILLIMETERSINCHES
A0.960 0.990 24.39 25.14
B0.465 0.510 11.82 12.95
C0.229 0.275 5.82 6.98
D0.216 0.235 5.49 5.96
E0.084 0.110 2.14 2.79
H0.144 0.178 3.66 4.52
J0.003 0.007 0.08 0.17
K0.435 ––– 11.05 –––
M45 NOM 45 NOM
Q0.115 0.130 2.93 3.30
R0.246 0.255 6.25 6.47
U0.720 0.730 18.29 18.54
__
STYLE 2:
PIN 1. SOURCE
2. GATE
3. SOURCE
4. DRAIN
CASE 316–01
ISSUE D
NOTES:
1. FLANGE IS ISOLATED IN ALL STYLES.
STYLE 2:
PIN 1. BASE
2. COLLECTOR
3. BASE
4. EMITTER
DIM MIN MAX MIN MAX
MILLIMETERSINCHES
A24.38 25.14 0.960 0.990
B12.45 12.95 0.490 0.510
C5.97 7.62 0.235 0.300
D5.33 5.58 0.210 0.220
E2.16 3.04 0.085 0.120
F5.08 5.33 0.200 0.210
H18.29 18.54 0.720 0.730
J0.10 0.15 0.004 0.006
K10.29 11.17 0.405 0.440
L3.81 4.06 0.150 0.160
N3.81 4.31 0.150 0.170
Q2.92 3.30 0.115 0.130
R3.05 3.30 0.120 0.130
U11.94 12.57 0.470 0.495
4
3
2
1
F
D
R
Q
L
K
EJB
A
H
N
C
U
7
MRF173 MRF173CQMOTOROLA RF DEVICE DATA
MRF173 MRF173CQ
8MOTOROLA RF DEVICE DATA
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the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and
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MRF173/D